By Carol Marrs, DCNP
When most people think of melanoma, they visualize a very irregularly shaped, asymmetrical, brown- to-black or multicolored growth that appears rather suddenly.
While this is not incorrect, this description only accounts for one type of melanoma, the most common type, which is known as superficial spreading melanoma1.
We often teach patients the “ABCDE rule” in order for them to be able to identify growths that could be melanoma2. We tell them to look for Asymmetrical lesions with irregular Borders, various Colors within the same lesion, a Diameter greater than 6 mm, and a lesion that is Evolving (changing) over time.
Although this mnemonic is helpful for identifying the most common type of melanoma, it is not helpful for identifying other major types: nodular, acral lentiginous, lentigo maligna, or amelanotic.
Nodular melanoma is much less common than the superficial spreading type, but has the potential to grow deep into the skin and spread to lymph nodes and distant organs more quickly1. It is important to identify and treat this type as soon as possible. Nodular melanomas are elevated above the surface of the skin, firm to the touch, and grow quickly. They are often confused for a blemish when they first appear. Usually, they are only one solid color and can be black, grey, brown, blue, red, pink, or skin colored.
Acral lentiginous melanoma occurs on the palms of the hands, soles of the feet, and within fingernails and toenails. This type is found most often among African American and Asian patients, and is rare in Caucasians1. Melanoma arising on the palms and soles usually presents as a brown to black irregularly pigmented patch and can be mistaken for a bruise or a trauma induced “blood blister.” In the nails, melanoma usually appears as a linear brown to black streak oriented vertically within the nail.
Lentigo maligna melanoma is often found in elderly individuals on the face, head, neck, and other areas frequently exposed to sun1. It initially appears as a flat, tan, freckle-like growth. This type grows very slowly over time and may develop darker brown areas within it.
Amelanotic melanoma has no pigment. This type presents as a new pink or skin colored growth. It can be flat, or elevated above the skin. This type is often confused with benign (non-cancerous) lesions or other types of skin cancers.
Hopefully, this article has conveyed the important message that melanoma is not always obvious. I recommend everyone check over their skin on a monthly basis in order to spot new or changing moles. Especially, look for the “ugly duckling” mole, which does not look similar to any of your other moles3. Everyone should have their skin evaluated by a medical professional at least once a year. The frequency of your skin checks will depend on your family history, your personal health history, your skin type, and the findings on your initial skin examination. Please have any suspicious growths checked promptly.
Carol Marrs, the author, is a Dermatology Certified Nurse Practitioner (DCNP) at the Skin Cancer & Cosmetic Dermatology Center. She practices at the Cleveland, TN and Ringgold, GA locations.
References:
- Skin Cancer Foundation. Types of melanoma. http://www.skincancer.org/skin-cancer-information/melanoma/types-of-melanoma. Accessed February 4, 2016.
- American Academy of Dermatology. What to look for: ABCDEs of melanoma. https://www.aad.org/public/spot-skin-cancer/learn-about-skin-cancer/detect/what-to-look-for. Accessed February 4, 2016.
- Skin Cancer Foundation. The Ugly Duckling Sign. http://www.skincancer.org/skin-cancer-information/melanoma/melanoma-warning-signs-and-images/the-ugly-duckling-sign. Accessed February 4, 2016.